<!DOCTYPE html>
<html>

<head>
    <meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
    <title>行政区域工具</title>
    <script type="text/javascript" src="http://api.map.baidu.com/api?v=1.2"></script>
</head>

<body>
    <div style="width:520px;height:340px;border:1px solid gray" id="container"></div>
    <p><input id="startBtn" type="button" onclick="startTool();" value="开启取点工具" /><input type="button"
            onclick="map.clearOverlays();document.getElementById('info').innerHTML = '';points=[];" value="清除" /></p>
    <div id="info"></div>
</body>

</html>
<script
    type="text/javascript">var map = new BMap.Map("container");                        // 创建Map实例map.centerAndZoom("北京", 11);     // 初始化地图,设置中心点坐标和地图级别var key = 1;    //开关var newpoint;   //一个经纬度var points = [];    //数组，放经纬度信息var polyline = new BMap.Polyline(); //折线覆盖物function startTool(){   //开关函数if(key==1){        document.getElementById("startBtn").style.background = "green";        document.getElementById("startBtn").style.color = "white";        document.getElementById("startBtn").value = "开启状态";        key=0;    }    else{        document.getElementById("startBtn").style.background = "red";        document.getElementById("startBtn").value = "关闭状态";        key=1;    }}map.addEventListener("click",function(e){   //单击地图，形成折线覆盖物    newpoint = new BMap.Point(e.point.lng,e.point.lat);    if(key==0){    //    if(points[points.length].lng==points[points.length-1].lng){alert(111);}        points.push(newpoint);  //将新增的点放到数组中        polyline.setPath(points);   //设置折线的点数组        map.addOverlay(polyline);   //将折线添加到地图上        document.getElementById("info").innerHTML += "new BMap.Point(" + e.point.lng + "," + e.point.lat + "),</br>";    //输出数组里的经纬度    }});map.addEventListener("dblclick",function(e){   //双击地图，形成多边形覆盖物if(key==0){        map.disableDoubleClickZoom();   //关闭双击放大var polygon = new BMap.Polygon(points);        map.addOverlay(polygon);   //将折线添加到地图上    }});</script>